Fastening element driving tool

ABSTRACT

A gun-type manually operable tool for driving a fastening element such as a nail into a work piece is disclosed. The tool comprises a driving means including a spring loaded ram means movable through an arming and driving stroke into contact with a nail situated at the driving station of the tool. A movable means engageable with the ram means operates to move the ram means through the arming stroke and release means is provided for effecting disengagement between the ram means and movable means at the completion of the arming stroke permitting movement of the ram means through the driving stroke. Alternate selectively operable release means are disclosed; one release means effecting automatic release of the ram means at the completion of the arming stroke and the other release means effecting non-automatic delayed-action release of the ram means at the completion of the arming stroke; the latter release mode being particular advantageous when using the tool in awkward hard to reach positions. Also disclosed is a special linkage means responsively connecting a manually operable actuating handle with the movable means. This linkage means advantageously includes a cam-cam follower means. The tool disclosed also includes a magazine-type of means for incrementally feeding fastening elements to the driving station. The feeding means is a guide supporting a row of fastening elements and a follow block which is spring biased forwardly of the guide to incrementally advance the row of fastening elements. The feeding means also includes a means for locking the follow block at the rear of the guide in order to permit convenient loading of fastening elements. Finally, the tool disclosed includes means whereby a fastening element may be conveniently driven into a recessed surface in a work piece, such as into a groove in decorative wall paneling.

United States Patent [1 1 Barrett et al.

[4 Oct. 21, 1975 1 FASTENING ELEMENT DRIVING TOOL [75] Inventors: Edward E. Barrett, Massapequa Park, L. l.; Morris Pinczewski, New York, both of NY.

[73] Assignee: Swingline, Inc., Long Island City,

22 Filed: ,Ian. 30, 1974 211 Appl. No.: 438,168

Related US. Application Data [63] Continuation-in-part of Ser. No. 328,700, Feb. l,

1973, abandoned.

[52] US. Cl 227/126; 227/132 [51] Int. Cl. 825C 5/10; 1325C 5/16 [58] Field Of Search 227/110, 120, 125, 126, 227/132, 146

[56] References Cited UNITED STATES PATENTS 1,845,617 2/1932 Metcalf 227/132 2,279,584 4/1942 Vogel 227/126 2,285,354 6/1942 Polzer 227/132 2,285,512 6/1942 Harley 227/132 2,298,123 10/1942 Harred r 227/126 2,326,540 8/1943 Krantz 227/132 X 2,548,736 4/1951 M0rberg............, 227/132 2,746,044 5/1956 Cujumano et al. 227/132 3,758,016 9/1973 Olney et al. 227/132 Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, or Firm-Pennie & Edmonds closed. The tool comprises a driving means including a spring loaded ram means movable through an arming and driving stroke into contact with a nail situated at the driving station of the tool. A movable means engageable with the ram means operates to move the ram means through the arming stroke and release means is provided for effecting disengagement between the ram means and movable means at the completion of the arming stroke permitting movement of the ram means through the driving stroke. Alternate selectively operable release means are disclosed; one release means effecting automatic release of the ram means at the completion of the arming stroke and the other release means effecting non-automatic delayedaction release of the ram means at the completion of the arming stroke; the latter release mode being par ticular advantageous when using the tool in awkward hard to reach positions. Also disclosed is a special linkage means responsively connecting a manually operable actuating handle with the movable means. This linkage means advantageously includes a cam-cam follower means. The tool disclosed also includes a magazine-type of means for incrementally feeding fastening elements to the driving station. The feeding means is a guide supporting a row of fastening elements and a follow block which is spring biased forwardly of the guide to incrementally advance the row of fastening elements. The feeding means also includes a means for locking the follow block at the rear of the guide in order to permit convenient loading of fastening elements. Finally, the tool disclosed includes means whereby a fastening element may be conveniently driven into a recessed surface in a work piece, such as into a groove in decorative wall paneling.

[4 Claims, 39 Drawing Figures US. Patent OCt. 21, 1975 Sheet 1 of 11 3,913,817

US. Patent Oct. 21, 1975 SheetZofll 3,913,817

US. Patent Oct.21,1975 Sheet4of1l 3,913,817

FIG. 7

FIG. 7A

US. Patent Oct. 21, 1975 SheetSofll 3,913,817

Gn 63) o\ r n I((87 68 W I U.S. Patent 0.21, 1975 Sheet6of11 3,913,817

FIG. I9

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FIG. l8

U.S. Patent Oct. 21, 1975 SheetSofll 3,913,817

U.S. Patent Oct. 21, 1975 Sheet9ofll 3,913,817

FIGJO Sheet 10 of 11 US. Patent 00:. 21, 1975 FIG.3|

FIG. 32

U.S. Patent Oct. 21, 1975 Sheetllofll 3,913,817

FASTENING ELEMENT DRIVING TOOL RELATED APPLICATIONS This application is a continuation-in-part of US. application Ser. No. 328,700 filed on Feb. 1, 1973. now abandoned.

BACKGROUND OF THE lNVENTlON This invention relates generally to fastening element driving tools and, more particularly, to a manually operable gun-type tool for driving a nail into a work piece as, for example, a short brad. The only available tools for driving a nail as far as it is known are pneumatically operated devices. Such devices are, however, complicated in structure and expensive to produce and use. In addition pneumatically operated tools require an air pressure source which only adds to the cost and detracts from the desirability of using such tools. Moreover, an air pressure source is not conveniently available at remote commercial construction sites where there exists a need for such a tool. Nor are such air pressure sources readily available to the homeowner. But in both commercial construction and in do-ityourself homeowner construction projects a nail gun is an extremely advantageous tool the use of which can save considerable time and effort. An example of one do-it-yourself project where such a gun is useful is the installation of wall paneling.

The present invention provides a self-contained portable light weight and relatively low cost tool for driving fastening elements into a work piece. The presently preferred embodiment of the invention shown in the drawings and described herein is specially constructed to drive nails, one at a time, into a work piece.

SUMMARY OF THE INVENTION A fastening element driving tool constructed in accordance with the teachings of the present invention includes a frame which supports a magazine means for feeding a plurality of fastening elements in succession to the discharge or driving station of the tool, a selectively operable driving means which acts to forcefully eject a waiting fastening element out of the tool and into the work piece and an actuating means for operating the driving means. The actuating means includes a handle and a specially constructed toggle-type linkage means which includes a cam-cam follower means. The linkage means is operatively connected between the handle and driving means. In the presently preferred embodiment of the invention, the cam-cam follower means is constructed such the driving means is easily actuated by applying a uniformly increasing manual force to the handle.

The magazine means of a fastening element driving tool constructed according to this invention includes an elongated guide for directing a strip of separable fastening elements to the driving station and a spring loaded follow block acting to automatically advance the fastening element strip incrementally forward toward the driving station along the guide after the lead fastening element in the strip is ejected by the driving means. The magazine feeding means also includes a locking means for holding the follow block at a position located at the end of the guide opposite the end thereof which is located adjacent the driving station of the tool. This permits the guide to be conveniently reloaded with a fresh strip of fastening elements without manually holding the follow block in place. in construction this locking means includes a cam-stop element positioned in the path of rearward movement of the follow block. As the follow block is moved rearward for reloading, it engages the camstop element thereby being cocked to an inclined attitude relative to the guide. This cocking action brings a stop surface on the follow block into engagement with a stop surface on the guide thereby releasably locking the follow block in said cocked attitude and preventing forward movement of the follow block along the guide until released by intentionally tilting the follow block back to its normal operating attitude.

The driving means of a tool constructed according to the present invention may include, as presently preferred, a spring loaded elongated ram member mounted for selected cyclical reciprocal movement away from the driving station and then back to the driving station under the force of the spring to eject a waiting fastening element. With such a construction a fastening element is driven each time the ram is moved through a complete cycle of movement. Each cycle involves two strokes; the first stroke or arming stroke being defined by movement of the ram away from the driving station and the second stroke or driving stroke by its movement back to the driving station. ln normal operation, the ram moves through a complete cycle without interruption between strokes. In other words the first and second strokes occur one after the other in a substantially continuous fashion. To provide this movement, the actuating means includes a ram lifting member engaging the ram and connected to the linkage means which operates to move the ram through its first stroke against the force of the spring. The actuating means further includes a release means which is operable, at the completion of the arming stroke, to disengage the ram lifting member from the ram thus permitting the ram to move through its driving stroke under the force of the spring. This two-stroke movement of the ram occurs in response to a single stroke or unidirectional movement of the operating handle.

In certain situations, however, it becomes difficult because of anatomical limitations for the user to apply sufficient pressure to the handle to move it through a complete stroke. For example, such difi'iculty is often experienced in cramped working space where awkward working positions must be assumed or, as another example, where the tool must be used to drive a fastening element into a work piece positioned at a level over the head or below the knees of the user. The tool of this invention is constructed to overcome this problem. This is accomplished by providing a delay-action release means which includes a restraining means for holding the ram and lifting member in engagement at the completion of the arming stroke thus holding the ram in place and an auxiliary non-automatic release means for disengaging the ram and lifting member thus allowing the ram to move through its driving stroke. The nonautomatic auxiliary release means includes an actuating lever which is easily actuatable withrelatively little force comparable to the force needed to trip a conventional light switch. Moreover, the automatic ram release mode of operation and the non-automatic ram release mode of operation are alternate modes selectable by the user depending upon circumstances with which he is confronted.

A tool constructed according to the present invention may also include specially constructed adopter means for accurately placing the fastening element in the decorative grooving found in most wall paneling without visually aligning the driving station with such grooves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation view of a tool constructed according to the present invention showing the operating handle in open position.

FIG. 2 is a side elevation view of the tool shown in FIG. 1 but with the operating handle in closed position.

FIG. 3 is a cross-sectional side elevation view of the tool shown in FIG. I depicting the driving means at the beginning of its arming stroke.

FIG. 4 is a cross-sectional side elevation view of the tool shown in FIG. 1 depicting the driving means at the completion of the arming stroke.

FIG. 4a is a front end view partially broken away of the tool shown in FIG. 4 depicting the driving means at the start of the driving stroke or completion of the arming stroke.

FIG. 4b is a cross-sectional view taken along the lines 4b4b of FIG. 4a.

FIG. 5 is a cross-sectional side elevation view of the tool shown in FIG. 2.

FIG. 5a is a front end view partially broken away of the tool shown in FIG. 5 depicting the driving means at the completion of its driving stroke.

FIG. 6 is a top elevation view of the magazine feeding means assembly of the tool shown in anyone of FIGS. 1-5.

FIG. 7 and 7a are partial cross-sectional views taken.

along the lines 77 of FIG. 6 showing the tool upside down for loading and showing the fastening element follow block in normal operating position and locked reloading position, respectively.

FIG. 8 is a perspective view of a fastening element strip which can be used with the magazine feeding means of the present invention.

FIG. 9 is a top plan view of the guide channel of the magazine feeding means when the tool is upside down for loading according to the present invention.

FIG. 10 is a front end view of the channel guide shown in FIG. 9.

FIG. 11 is a cross-sectional view of the channel guide taken along the lines II-ll of FIG. 9.

FIG. 12 is a rear end view of the guide channel shown in FIG. 9.

FIG. 13 is a front end view of the follow block of the magazine feeding means.

FIG. 14 is a top plan view of the follow block shown in FIG. 13.

FIG. I5 is a front end view of the tool shown in FIG. I equipped with a fastening element locating adapter in inoperative position.

FIG. 15a is a side elevation view of the tool showing the locating adapter in inoperative position.

FIG. I6 is a front end view of the tool shown in FIG. 1 equipped with a fastening element locating adapter in operative position.

FIG. 16a is a side elevation view of the tool showing the locating adapter in operative position.

FIG. I7 is a bottom view of the tool shown in FIG. I equipped with a locating adapter.

FIG. 18 is a partial cross sectional elevational view of an alternative embodiment showing the ram in its armed position;

FIG. 19 is a partial sectional elevational view of the alternative embodiment showing the ram in its driving position; and

FIG. 20 is a similar view showing the ram returned to its rest position after driving.

FIG. 21 is a front end view partially broken away of the embodiment shown in FIGS. 18-20.

FIG. 22 is a partial side elevational view of the showing lever 113 in its forward position;

FIG. 23 is a similar view showing lever [I3 in its rear ward position;

FIG. 24 is an elevational view of the other side of the tool with handle 9 in its upper position;

FIG. 25 is a side elevational view with the handle down and latched;

FIG. 26 is a partial sectional elevational view showing lever I13 turned to release the ram;

FIG. 27 is a partial sectional elevational view showing the releasing button depressed; and

FIG. 28 is a similar view showing the handle released.

FIG. 29 is a side elevational view of the tool having an alternative embodiment showing the tool in a rest position.

FIG. 30 is a side elevational view of the tool shown in FIG. 29 with the tool in a position just prior to driv- FIG. 31 is a side elevational view of the tool shown in FIG. 29 at completion of the driving stroke.

FIG. 32 is a section view taken along lines 32-32 of FIG. 30.

FIG. 33 is a section taken along lines 3333 of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION With reference to FIGS. 1 and 2, a fastening element driving tool constructed according to the present invention comprises a frame indicated generally by reference numeral 10. The frame 10, which includes a gripping element 3 as shown, supports a housing for the operating components of the tool. The housing includes fastener-holding channel I and sheath 2. A cover 4 for channel 1 is pivotally secured to the rear end of the frame by hinge pin 5. The cover 4 is swingable, upon release of cover latch 6, about hinge pin 5 to expose, for purposes of loading, the magazine-type fastening element feeding means contained within case channel 1. This feeding means, which will be described more fully hereinafter, is operable to successively feed indi vidual fastening elements one at a time to the driving station of the tool which is indicated generally by reference numeral 7. Sheath 2 houses the component parts of a selectively operable fastening element driving means which, upon activation, acts to drive a waiting fastening element situated at the driving station out of the tool and into a work piece. The driving means will also be described more fully below. The forward end portion 8 of the frame supports a specially constructed actuating means for operating the driving means. The actuating means includes. as shown in FIGS. 1 and 2, an actuator handle 9 pivotally connected to frame 10 by hinge pin 11 and spring biased toward its open position (FIG. I) by arm 22a of torsion spring 22 as shown in FIG. 3. The actuating means further includes a specially constructed linkage means responsive to the actuator handle which acts to cock the driving means. The linkage means, which is not shown in FIGS. 1 and 2, will also be described more fully below. As shown handle 9 carries at its forward end a hand guard 12 which is also mounted on hinge pin 11 and fixed in place relative to handle 9 by rivet means (not shown in FIGS. 1 and 2). For the purpose of locking the handle 9 in the fully closed or locked position shown in FIG. 2, a handle latch 13 pivotally secured to the forward end 8 of gripping handle 3 by hinge pin 14 is provided. Handle latch 13 is provided with a thumb rest 15 for the purpose of permitting convenient rotation thereof from the position shown in FIG. 2 to the position shown in FIG. 1 to thereby permit pivotal movement of handle 9 to its open or unlocked position as shown in FIG. I. To release handle 9, it is helpful to depress it slightly from its locked position as shown in FIG. 2 in the direction of arrow 16. Such movement it will be recognized slightly separates contacting locking surfaces 17 and 18 of handle 9 and latch 13, respectively, to provide enough clearance between these locking surfaces permitting easy release of the handle. Similarly, it is helpful, for purposes of releasing cover 4, to depress cover 4 slightly from its closed position as shown in FIG. 2 in the direction of arrow 17. This movement provides sufficient clearance between locking surfaces 19, 20 on cover 4 and cover latch 6, respectively, to permit latch 6 to be easily pivoted from its locked position to its open position (as indicated by arrow 21 in FIG. 2) thereby separating locking surfaces 19, 20 to allow cover 4 to be swung open. As will be seen in FIG. 3, cover latch 6 is itself spring biased in locked position by arm 22b of torsion spring 22 thus insuring against accidental opening of the cover during operation. Handle latch 13, on the other hand, is held securely in its locked position with its locking surface 18 engaging locking surface 17 of handle 9 by force of engagement between these locking surfaces created by arm 22a of torsion spring 22 biasing the handle 9 toward its open position. Thus handle 9 is safely prevented from flying accidently into open position when the tool is not being used.

It should be noted at this point in the description that the embodiment of the invention shown in the drawings is constructed for use in driving relatively short nails into a work piece. Such nails are separably connected together in a self-supporting strip 23 as shown in FIG. 8 and these nails are utilized in strip form by the tool shown in the drawings as will be more fully understood as the description proceeds. However, it will become readily apparent that many structural features of the present invention can be utilized in a tool intended for driving other fastening elements as, for example, conventional two-prong staples.

Referring now to FIGS. 3, 4 and 5, the driving means contained within sheath 2 includes an elongated hollow ram member 25 which is mounted for selective cyclical two-stroke movement between two longitudinally spaced apart positions within sheath 2 each time a nail is driven from the tool. In one of these positions, ram 25 is situated in the lower portion of sheath 2 as shown in FIGS. 3 and 5. In the other position, ram 25 is situated in the upper portion of sheath 2 as shown best in FIG. 4. As will be more fully explained below in that portion of the description which described the operation of the tool upon each driving of a nail the ram 25 is moved through one complete cycle; i.e. from its initial rest position shown in FIG. 3 upward to the driving position shown in FIG. 4 (such upward movement representing the upstroke of the cycle) and then down again to its rest position shown in FIG. 4 (such downward movement representing the downstroke of the cycle). For a purpose to be described more fully hereinafter the rearwardly facing wall 250 of ram 25 is equipped with a shear-formed lifting lug 25d which moves in slot 146 formed in the rear wall 2d of sheath 2 during the upstroke and downstroke of the ram.

Connected to the ram 25 for movement therewith is a driver blade 26. The driver blade 26 is secured to ram 25 by spaced shear-formed lugs 27 which are received in spaced openings 28 in driver blade 26. The driving end of driver blade 20 is formed with a flat ended tongue 29 which during the downstroke is brought into contact with the head 30a of a nail 30 to be driven. The driver blade 26 and connected ram 25 are guided within sheath 2 by a slide-way defined by shear-formed guide detents 31 projecting inwardly from the front wall 2a of sheath 2 on opposite sides of driver blade 26 as best shown in FIG. 4b.

For the purpose of enabling ram 25 and driver blade 26 to undergo downward movement with sufficient force to drive nail 30 out of the tool with sufficient force to penetrate a work piece, a composite compres sion spring 32 is provided. As shown, this spring is disposed within bore 25a of ram 25 with one of its ends resting on the bottom plate 25b of ram 25 and with its other end abutting the top plate 2b of sheath 2. An inwardly protruding boss 2c is carried by the top plate 2b of sheath 2 for the purpose of retaining spring 27 aligned in bore 25a of ram 25. With this construction, it will be recognized that the ram 25 and thus driver blade 26 are biased toward the driving station 7 of the tool.

For the purpose of cocking the ram (i.e. lifting it to driving position) and releasing it so that it may be moved forcefully downward under the force exerted upon it by compression spring 32 an actuating means, previously mentioned, is provided. The actuating means comprises handle 9 and a linkage means operatively connected between ram 25 and handle 9. The linkage means comprises a ram lifter member 42, a pivotally mounted lever link 40 and a special cam-cam follower means. The link 40 is pivotally mounted at a point approximately midway along its length on stationary link pin 41 to define two arms 40a and 40b situated on either side of link pin 41. The ram lifter 42 pivotally mounted on the forward end of lever arm 40a for movement therewith by pin 43. The cam-cam follower means includes a curved plate 50 defining a cam surface and a cam follower 51. The cam plate 50 is carried by lever arm 40b as shown. The follower 51 comprises a rotatable circular roller 48 rotatably mounted on bracket 45 which is secured to handle 9 by rivets 46. As shown, the left hand rivet 46 as viewed in FIGS. 3-5 also secures the hand guard 12 to handle 9. Torsion spring 22, previously mentioned, is looped about pivot pin 41. As shown one arm of spring 22 engages the latch 6 for cover 4 and the other ann engages the underside of cam plate 50. Spring 22 is therefore operative to bias the cover latch 6 in the locked position shown in FIG. 2 and to urge rotation of link 40 about pin 41 in a counter clockwise direction (as viewed in the drawings) thus moving handle 9 into the open position and ram lifter 42 into a position adjacent ram stop 47 and buffer 47a.

As mentioned above, ram lifter 42 is pivotally connected to link 40 by pivot pin 43. A second torsion spring 23 is looped about pivot pin 43 as shown. One arm of spring 23 engages cam plate 50 and the other arm engages lifter plate 420 on ram lifter 42. With this arrangement the ram lifter plate is urged into engagement with the lifting lug on the ram. Spring 23 insures that this engagement is maintained during the upstroke or arming stroke of the ram until such time as these two members are disengaged by the coaction of cam surface 42b of ram lifter 42 with the handle hinge pin II as will be more fully explained below.

Now, with particular reference to FIGS. 6l4 the magazine means for feeding fastening elements to the driving station of the tool includes a guide 60 and a spring-biased follow block 61. Guide 60, which is con tained with magazine housing I of the tool, defines an elongated open ended channel 62 for receiving the strip of separable nails previously mentioned. The guide 60 is vertically retained within housing I at its forward end by tabs 67 projecting laterally outward from the forward end of both sides of channel 62; these tabs 67 extending into aligned recesses 71 in housing 1 as shown in FIG. 4a. At its rear end, the guide is retained in place by laterally projecting tabs 68 projecting from the rear end of channel 62; and engaging the respective side walls of housing 1. The channel 62 is also retained in place at its rear end by means of pierced tab 69 extending rearwardly from the end of one tab 68 Tab 69 engager pin as shown.' Here it should be noted that the driving station of the tool is located immediately in front of the forward retaining tabs 67. In other words, downward movement of the ram brings the driver blade 26 past the front end of channel 62 immediately in front of or adjacent to retaining tabs 67.

The follower block 61 is slidable longitudinally within channel 62 in contacting relation with the last or rearmost nail in the strip. As shown, one side of the open ended channel 62 carries a flange 63 which forms a track for retaining the follow block 61 within channel 62 by means of bent over tab 64 on the follow block.

To incrementally advance the nail strip to the driving station 7 of the tool, the follow block 61 is urged forwardly of the channel toward the driving station by means of spring 65. One end of spring 65 is connected to the follow block about hook 66 which extends laterally outward from the follow block on the non-flanged or straight side of channel 62. The other end of spring 65 is attached to hook tab 73 which projects laterally outward from the non-flanged or straight side of channel 62. Intermediate its ends, spring 65 extends alongside the straight side of channel 62 about a freely rotatable roller 74 mounted on housing 1 (FIGS. 3-5).

The follow block 61 further includes a thumb rest tab 72 which is provided for the purpose of facilitating convenient manual movement of the follower block to its rearmost position within the channel for the purpose of reloading the tool with a fresh strip of nails. For the purpose of retaining the follow block at its rearmost position while the replacement strip is being loaded, a specially constructed locking means is provided. As best shown in FIGS. 7 and 7a this locking means includes an upstanding cam stop 80 carried by casing la of channel case 1 adjacent the rearmost position of the follow block in channel 62. This cam stop is equipped with a forwardly facing slopping cam surface 81 which coacts with the rearwardly facing rear edge 82 of hook tab 66 on follow block 61. As the follow block is moved rearward within channel 62, this rear edge 82 cams against cam surface 81 causing the entire follow block to tilt from the normal operating position shown in FIG. 7 into the tilted position shown in FIG. 70. To permit tilting movement of the follow block its bottom surface 84 is tapered toward the rear at 84a. Tilting of the follow block as above described causes the forwardly facing front edge 85 of web 86 on the follow block to engage the rearwardly facing rearmost edge 87 of channel flange 63 of guide 60 to thereby hold the follower block in tilted position at the rear of channel 62. Broadly defined, therefore, the rear edge 87 of channel flange 63 and the front edge 85 of follow block 61 act as coacting stop surface preventing forward movement of the follow block within channel 62.

After loading of a new nail strip, the follow block may be released simply by exerting light pressure on its forward end either manually or by closing the cover to cause disengagement of stop surfaces 87 and 85. Upon such disengagement the follow block will be urged by spring 65 into contact with the rearmost or trailing nail of the strip and will thus, after each driving of the leading nail, advance the staple strip incrementally through channel 62, in turn, bringing each nail of the strip successively into driving position at the driving station of the tool.

The operation of the embodiment thus far described is as follows. The cover latch 6 is first pulled back to permit cover 4 to be swung into open position exposing the nail strip guide and follow block. The follow block is then locked in the loading position at the rear of the guide as previously described. Next, a strip of nails is loaded into the guide channel and the follow block released in the manner described above thus moving the nail strip forward in channel 62 to bring the first staple in the strip into driving position at the driving station of the tool. The cover is then swung to a closed position and snapped into locked condition by cam action between cam surfaces 40, 4b of locking tabs 40, 4d on cover 4 and cover latch 6, respectively. The handle latch 13 is then depressed as previously described freeing the handle 9 which will be automatically moved to the position shown in FIG. 3 by the action of arm 22a of spring 22. With this movement of the handle 9, the various component parts of the linkage means assume the position shown in FIG. 3 wherein it will be noted that the ram lifting plate 42a on ram lifter 42 is disposed in contact with ram lifting lug 25 d and ram 25 which is in its lowermost position resting against the shock absorbing buffer pad 470 supported by ram stop 47. In this position it will also be seen that the roller 48 is in contact with the endmost portion of the cam sur face defined by cam plate 50. To drive the tool the operator depresses handle 9 to move it toward its closed position adjacent gripping portion 3 of the frame. This movement causes relative rolling movement between roller 48 and cam plate 50 along contacting surfaces defined by the periphery of roller 48 and the cam surface. In tum pivotal movement of link 40 in a clockwise direction (as viewed in FIG. 3) ensues causing ram lifter 42 to move upward to thereby lift the ram 25 and connected driver blade 26 to the position shown in FIG. 4 which is the completion of the arming stroke.

Just prior to reaching this position, the cam surface 42b of ram lifter 42 is brought into engagement with hinge pin 11 thereby causing clockwise movement of ram lifter 42 relative to link 40 away from ram 25. This movement it will be recognized causes disengagement of the ram lifting plate 42a and the ram lifting lug 25d thus releasing the ram for downward movement (i.e. its driving stroke) toward the driving station under the force exerted by compression spring 32.

Release of the ram for downward movement occurs precisely at the point at which roller 48 traverses the crest 40c of curved cam surface defined by cam plate 50. The curvature of this cam surface is carefully controlled and defines a developed curve which advantageously requires that a uniformly increasing force be applied to handle 9 to move the ram along its arming stroke through the point of release.

Simultaneously with movement of roller 48 over crest 40c and release of ram 25 from engagement with ram lifter 42, the ram begins forceful downward movement toward the driving station thereby bringing the flat end of the driver blade tongue into forceful contact with the head of the waiting nail to drive it out of the tool into the work piece.

After driving of the nail, the pressure exerted by the tool operator on handle 9 may be released thereby permitting the handle and linkage means to automatically move back their initial position as shown in FIG. 3 for redriving. At the same time the next nail in the strip is ready to be advanced by the spring loaded follow block into driving position at the driving station during the next arming stroke. This nail may then be advanced and driven by again depressing handle 9 as described above in connection with the first driving of the tool.

The embodiment of this invention described above in connection with FIGS. 1-14 is intended primarily for use in driving nails into a flat surface of a work piece. Thus it will be noted that the underside of magazine cover 4 is substantially flat to give the tool good stability when it is held against a work piece. Several applications however require that a nail be driven into a depressed surface of a work piece. An example of such an application is the fastening of interior decorative wood paneling to a wall. Such panels are generally provided with longitudinal grooves to enhance the beauty and decorative effect achieved by such panels. In such applications it is usually most advantageous to drive the fastening nails into the grooves of the panel where they are not readily noticeable to the naked eye. For the purpose of conveniently determining that the tool is properly located on the work piece to drive the nail into the groove or recess, the bottom of magazine cover 4 may be formed with a longitudinal rib 90 which projects outward beyond the otherwise nonnally flat surface defined by the bottom cover. As shown in FIG. 17 and 15a the magazine cover tapers away from the bottom surface of the rib at point 4e. lnteriorly of the cover, this rib defines a longitudinal groove for receiving the sharpened nail ends of the strip as it is fed through channel 62. The rib is located so that at its lowermost position the driver blade tongue 29 lies substan tially flush with the exterior surface of the rib. With this arrangement the tool may simply be placed upon a work piece and moved about until the rib 90 lies within the groove. Proper alignment is readily determined by feel inasmuch as the tool will naturally catch as the rib settles into the groove.

To provide a tool equipped with a locating rib with the capability to nail effectively on a flat surface, a swivel-type adaptor block is rotatably mounted on a supporting stud 95 projecting outwardly from the front wall of sheath 2. As shown, the back side of swivel block and sheath 2 are urged into tight contact by means of spring washer 97.

The adaptor block 94 is accentrically mounted on the stud so that the distance between the center point of the mounting stud 95 and edge 96 is less than the distance between the center point of the mounting stud to the parallel edge 92 by a distance equal to the extent of projection of rib 90. With edge 92 of the adaptor block 94 in the position shown in FIGS. 15 and 15a, the bottom of cover 4 is effectively fiat. This is due to the fact that edge 92 projects beyond the bottom surface 91 at the front of the cover by distance equal to the distance by which the rib projects beyond the same surface. Thus the effect of rib 90 is cancelled and, effectively, a flat surface is presented to the work piece. By rotating the adaptor block 180 degrees so that edge 96 occupies the same general position formerly occupied by edge 92, the rib 90 again becomes effective. This is due to the spacing between edge 96 and the center point of mounting stud 95 which permits the rib to project beyond edge 96 as shown in FIGS. 16 and 16 a. In this position edge 96 lies substantially flush with the bottom 91 of cover 4 as shown. To rotate the swivel block in order to bring to the appropriate edge 96, 92 of the adaptor block into position, the block may be simply pulled away from the sheath against the force of the spring washer and rotated to the desired position and released whereupon it will snap back into tight engagement with the sheath under the force exerted by the spring washer.

When using the tool of this invention to nail into a recessed surface it is frequently important that the nail be driven into the recessed surface so that its head lies flush with the recessed surface. This can be accomplished simply by adjusting the position of the ram stop 47 relative to the driving station so that the driver blade tongue 29 at its lowermost point of travel on the driving stroke extends out of the tool into contact with recessed surface. Such a construction is shown in FIGS. 18-21. Referring to FIG. 18, the ram 25 and driver blade 26 are shown at the completion of the arming stroke just prior to being released into the driving stroke. In FIG. 19 and 20, the ram and driver blade are shown at the completion of the driving stroke where it will be seen that the driver blade tongue 29 projects exteriorly of the tool into contact with the recessed surface 100 in work piece 101. For the purpose of retracting the driver blade tongue 29 back into the tool so that it will not accidently be broken 06' in moving the tool to a new driving position, a spring 102 is provided. This spring 102 is secured to the bottom of ram 25 as shown. Spring 102 functions to move the ram slightly upward at the completion of the driving stroke to the position shown in FIG. 21 in which position it will be seen that the driver blade tongue 29 is located within the tool. As shown in FIGS. 18-21, the shock absorbing buffer pad 47a is annular in shape to define a central opening 47b accommodating spring 102. That is, spring 102 is received through opening 47b into direct contact with ram stop 47.

An alternative to the construction of FIGS. 18-21, is shown in FIGS. 29-32 in which the ram stop 47 and buffer 470 are positioned to permit ram 25 to travel in the driving stroke a sufficient distance so that tongue 29 extends below the bottom of tool (FIG. 31) and in which the ram is initially raised after the driving stroke by an initial ram lifter arrangement 140 rather than by spring 102 as shown in FIG. 20. This action is useful in countersinking the fastening element.

With further reference to FIGS. 29-32, ram lifter arrangement 140 includes lever member 141 pivotable about sheath pin 142. In FIG. 29, the actuator handle 9 has been raised causing ram lifter 42 to descend and to push down the right hand end of lever member 141 which in turn caused the left hand end of the member 141 to initially lift ram 25 to thereby retract the driving blade tongue 29 back toward the bottom level of sheath 2 until lever member 141 engaged the bottom of rear wall 2d. The ram 25 is thereafter lifted by ram lifter member 42 to the top of the sheath where it is released to descend in a driving stroke as herein elsewhere described. As ram 25 is further raised by member 42 moving upwardly, lever member 141 rotates by the force of spring 143 counterclockwise to the position shown in FIG. 30. At the end of the driving stroke (FIG. 31), the ram 25 is again engaged by lever member 141 and ready for the initial ram lifting step when ram lifter member 42 is moved downward against the right hand end of lever member 141.

As mentioned previously, applying sufficient pressure on handle 9 to effect driving of the tool may be difficult due to the awkward position in which the tool must be held during use. To overcome this problem, a tool constructed according to this invention may be operated in an alternate mode which permits a nonautomatic delayed-action release of the ram at the completion of the arming stroke without applying pressure to the handle. For this purpose a selectively operable auxiliary means for releasing the ram at the completion of the arming stroke is provided. The selectively operable means includes a retaining means for indefinitely holding the ram in the position it occupies at the completion of the arming stroke and a manually operable switch means for releasing the ram at the proper time to undergo the driving stroke. As will become apparent as the description of the delayed-action ram release means proceeds, the continuous rarn release means previously described in connection with FIGS. 1-14 and the delayed-action release means presently to be described can both be advantageously incorporated in the same tool so that the user is provided with the option of selecting the appropriate mode for the particular job at hand.

With reference now to FIGS. 2227, the auxiliary ram release means includes a pin element 111 which supports handle 9 for pivotal movement as above described. Pin 111 is generally circular in cross-sectional shape and is provided with a longitudinally extending flat area 112.

Pin 111 is mounted on frame 10 for rotation between two angular positions. One of these positions is shown in FIG. 25 and the other in FIG. 26.

In the position shown in FIG. 25, pin 111 is disposed alongside the path of upward movement of ram lifter 42 such that when the ram 25 reaches the completion of the arming stroke the surface 42b of ram lifter 42 facing the ram 25 is disposed in face-to-face contact with flat area 112. In the position shown in FIG. 26, pin 111 is disposed in the path of upward movement of ram lifter 42 in the same manner as is pin 11 described in connection with the embodiment shown in FIGS. 1-21. Thus, with pin 111 in this position the ram release means functions in the same manner as previously described.

For moving pin 111 between the two angular positions, a manually operable lever 113 is attached to one end of pin 111 exteriorly of the sheath 2 as best shown in FIGS. 22-24. Hand guard 12 is provided with two holes 114 one of which, depending on the angular position of pin 111, receives a small detent 115 projecting from the inwardly facing surface of lever 113 to thereby hold pin 111 in place. Detent 115 snaps into holes 114 as lever 113 is rotated.

When it is desired to delay release of the ram at the completion of the arming stroke, pin 111 is moved to the position shown in FIG. 24 prior to initiation of the arming stroke by depressing handle 9. As the ram 25 and ram lifter 42 approaches the completion of the arming stroke, pin 111 rotates to the position shown in FIG. 25; the ram lifter sliding alongside flat area 112 without being pivoted out of engagement with the ram lifting lug 25d. The ram 25 is locked in this position by a retaining means which comprises a releasable latch means for holding the handle 9 in its then depressed position. As shown in FIGS. 24 and 25, this latch means includes a locking bolt mounted for sliding pivotal movement on hinge pin 5 extending through a slot 121 in the lower end of bolt 120. The upper end of bolt 120 defines a lip 125 which is engageable with a lip 9a on the end of handle 9. The locking bolt 120 carries a push bottom 126 which extends through a slot 127 located in the rear end plate 128 of gripping portion 3. Locking bolt 120 is biased pivotally outward into engagement with end plate 128 by arm 1290 of spring 129 attached to bolt 120 at 130. The other arm 12911 of spring 129 is provided with a knuckle 129a. This knuckle 129C acts to hold bolt 120 relative to pin 5 in either the up position (FIG. 24) or the down position (FIG. 28) for a purpose to be described hereinafter.

To set bolt 120 in position for delayed release of the ram, bolt 120 is moved from the continuous driving down position to the up position by moving push buttom 126 in an upward direction to the position shown in FIG. 24. Bolt 120 is held in the up position during the delayed-action driving mode of operation by the engagement between knuckle 129v of spring arm 12% in the manner shown in FIG. 24. As handle 9 is depressed to bring ram 25 into its position at the completion of the arming stroke, the external surface of lip 90 contacts cam surface 131 on bolt 120 causing it to pivot inward about pin 5, in turn, moving lip 125 into a position slightly above lip 9a at which time lips 125 and 9a snap automatically into locking engagement under the force exerted on bolt 120 by spring am 1290. Release of the handle 9 for subsequent driving of the tool is accomplished simply by depressing push button 126 as indicated by the arrow in FIG. 27 causing disengagement of lips 125 and 9a.

With handle 9 locked in place, the ram will be held indefinitely in the position shown in FIG. 25. To release the ram so that it may move through the driving stroke to drive a fastening element out of the tool, pin 111 is rotated from the position shown in FIG. 25 into the position shown in FIG. 26. This rotation of pin 111 causes ram lifter 42 to pivot inward breaking engagement between the ram lifter plate 42a and ram lifting lug 25d thus releasing ram for downward movement through its driving stroke. Rotation of pin III as aforesaid is, of course, effected by manually moving lever 113 with light finger pressure to move it from the position shown in FIG. 25 to the position shown in FIG. 26.

it is to be pointed out that the delayed-action ram release just described is optional to the user of the tool. By initially setting pin 111 in the angular position shown in FIG. 22, release of the ram will be automatic as it reaches the completion of its arming stroke in the same manner as previously described in connection with the embodiment shown in FIGS. l2l. Thus the continuous automatic ram release and non-automatic delayed action ram release are alternate modes of operation which can be selected at will by the user depending upon circumstances. As mentioned previously, the delayed action mode is particularly advantageous when using the tool in awkward hard to reach positions where sufficient hand pressure is difficult or impossible to apply to the handle 9. It should be noted that for continuous driving the locking bolt 120 is moved into the down position by depressing push button 126 and sliding it downward on pin 5. The bolt is held in the down position during the continuous driving mode of operation by engagement between knuckle 1290 of spring l29b in the manner shown in FIG. 28. Also, it should be noted that lever 113 is held in the position shown in FIG. 26 as the handle 9 is moved to open position after each driving by abutment against latch 6 as shown best in FIG. 23. And, lever 113 is automatically returned to the driving position shown in FIG. 25 during the next arming stroke.

We claim:

1. A tool for driving a fastening element into a work piece comprising:

a. a frame;

b. magazine means mounted on the frame for feeding a fastening element to a driving station;

c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and movement back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station;

d. movable means engageable with the ram means for advancing the ram means through the arming stroke, said movable means including:

1. a pivotally mounted member engaging the ram means during the arming stroke; and

2. spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke;

e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke, said release means including:

a pin element mounted on the frame for rotation between a first angular position where a first surface on the pin element is disposed alongside the path of movement of the pivotally mounted member without causing the member to rotate and a second angular position where a second surface on the pin element is disposed in the path of movement of the pivotally mounted member to cause the member to rotate, said pin being disposed in the first angular position during the arming stroke; and

a manually operable lever means connected to the pin element for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member out of engagement with the ram means to thereby permit movement of the ram means through the driving stroke.

2. A tool according to claim 1 wherein:

a. said pin element is generally circular in crosssectional shape;

b. said pin element first surface is defined by a flat area on said pin; and

c. said pin element second surface is defined by the rounded outer surface of the pin element.

3. A tool for driving a fastening element into a work piece comprising:

a. a frame;

b. magazine means mounted on the frame for feeding a fastening element to a driving station;

c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station;

said magazine means including:

l. an elongated guide slidably guiding a plurality of fastening elements in a row leading to the driving station situated at the front end of the guide;

2. a follow block mounted for longitudinal move ment relative to the guide in contact with the rear fastening element in the row;

3. spring means normally urging the follow block forward along said guide to incrementally advance the row of fastening elements toward the driving station upon completion of the arming stroke;

4. locking means for holding the follow block at the rear end of the guide for purposes of reloading the tool with a new row of fastening elements, said locking means including:

a. normally disengaged rearwardly and forwardly facing stop surfaces on the guide and follow block, respectively;

b. a cam stop element on the guide having a sloping forwardly facing cam surface positioned in the path of rearward movement of the follow block; and

c. a rearwardly facing surface on the follow block engageable with the sloping cam surface to tilt the follow block into an inclined attitude to bring said normally disengaged stop surfaces into engagement thereby preventing forward movement of the follow block along said guide.

e. movable means engageable with the ram means for advancing the ram means through the arming stroke:

f. release means pivotally mounted on the frame for effecting disengagement between the ram means and the movable means upon completion of the arming stroke;

g. actuating means for moving the movable means including:

l. a movable handle; and

2. linkage means including cam-cam follower means connected between the handle and the movable means;

h. said movable means includes a pivotally mounted member engaging the ram means during the arming stroke and spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke:

i. said linkage means includes:

1. a link member pivotally mounted on the frame at a point intermediate it ends, said pivotally mounted member being pivotally mounted on one end of the link member;

2. a plate member defining a cam surface mounted on the other end of the link member; and

3. a cam follower mounted on the handle and engaging said cam surface.

j. said release means includes:

l a pin element mounted on the frame for rotation between a first angular position where a first surface on the pin element thereof is disposed alongside the path of movement of the pivotally mounted member without causing the member to rotate and a second angular position where a surface on the pin element thereof is disposed in the path of movement of the pivotally mounted member to cause the member to rotate, said pin being disposed in the first angular position during the arming stroke; and

the pin element for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member to pivot the pivotally mounted member out of engagement with the ram means to thereby permit movement of the ram through the driving stroke.

4. In a tool for driving a fastening element into a recessed surface in the work piece, said tool including a housing and means within the housing operable upon activation to drive said fastening element from a driving station within the housing into the recessed surface, said tool being adapted to be held against the work piece during driving the improvement in combination therewith which comprises:

a. a projection aligned with the driving station and protruding from the surface of tool which contacts the work piece during driving, said projection being adapted to extend into said recess in the work piece;

b. an adaptor block rotatably mounted on the housing and having:

1. a first edge spaced from the axis of rotation of the adaptor block by a predetermined distance approximately equal to the distance between said axis of rotation and said work piece contacting surface of the tool; and

2. a second edge parallel to the first edge spaced from said axis of rotation by a distance approximately equal to said predetermined distance plus the distance which said projection protrudes from said work piece contacting surface.

5. The improvement according to claim 4 wherein:

a. said adaptor block includes a recess extending through said first and second edges, said last mena manually operable lever means connected to tioned recess being adapted to receive a portion of the housing into mating engagement therewith;

b. said adaptor is spring biased into mating engagement with said housing; and

c. said projection defines a tapering longitudinal rib.

6. A tool for driving a fastening element into a work piece comprising:

a. a frame;

b. magazine means mounted on the frame for feeding a fastening element to a driving station, said magazine means including:

1. an elongated guide slidably guiding a plurality of fastening elements in a row leading to the driving station situated at the front end of the guide;

2. a follow block mounted for longitudinal movement relative to the guide in contact with the rear fastening element in the row;

3. spring means normally urging the follow block forward along said guide to incrementally advance the row of fastening elements toward the driving station upon completion of the driving stroke; and

4. locking means for holding the follow block at the rear end of the guide for purposes of reloading the tool with a new row of fastening elements;

c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station;

(1. movable means engageable with the ram means for advancing the ram means through the arming stroke;

e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke;

f. actuating means for moving the movable means including:

l. a movable handle; and

2. linkage means including cam-cam follower means connected between the handle and the movable means.

7. A tool according to claim 6 wherein:

21. said locking means includes:

i. normally disengaged rearwardly and forwardly facing stop surfaces on the guide and follow block, respectively;

2. a cam stop element having a sloping forwardly facing cam surface positioned in the path of rearward movement of the follow block; and

3. a rearwardly facing surface on the follow block engageable with the sloping cam surface to tilt the follow block into an inclined attitude to bring said normally disengaged stop surfaces into engagement thereby preventing forward movement of the follow block along said guide. 8. A tool according to claim 6, wherein: a. each of said fastening elements is a nail; b. said guide defines an elongated channel for slidably receiving a row of said nails; and c. the follow block is slidably mounted for longitudinal movement within said channel. 9. A tool according to claim 6 wherein the stop surfaces, the cam stop element, the rearwardly facing sur- 

1. A tool for driving a fastening element into a work piece comprising: a. a frame; b. magazine means mounted on the frame for feeding a fastening element to a driving station; c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and movement back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station; d. movable means engageable with the ram means for advancing the ram means through the arming stroke, said movable means including:
 1. a pivotally mounted member engaging the ram means during the arming stroke; and
 2. spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke; e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke, said release means including: a pin element mounted on the frame for rotation between a first angular position where a first surface on the pin element is disposed alongside the path of movement of the pivotally mounted member without causing the member to rotate and a second angular position where a second surface on the pin element is disposed in the path of movement of the pivotally mounted member to cause the member to rotate, said pin being disposed in the first angular position during the arming stroke; and a manually operable lever means connected to the pin element for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member out of engagement with the ram means to thereby permit movement of the ram means through the driving stroke.
 2. a manually operable lever means connected to the pin element for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member to pivot the pivotally mounted member out of engageMent with the ram means to thereby permit movement of the ram through the driving stroke.
 2. spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke. e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke, said release means includes:
 2. a follow block mounted for longitudinal movement relative to the guide in contact with the rear fastening element in the row;
 2. a cam stop element having a sloping forwardly facing cam surface positioned in the path of rearward movement of the follow block; and
 2. spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke; e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke, said release means including: a pin element mounted on the frame for rotation between a first angular position where a first surface on the pin element is disposed alongside the path of movement of the pivotally mounted member without causing the member to rotate and a second angular position where a second surface on the pin element is disposed in the path of movement of the pivotally mounted member to cause the member to rotate, said pin being disposed in the first angular position during the arming stroke; and a manually operable lever means connected to the pin element for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member out of engagement with the ram means to thereby permit movement of the ram means through the driving stroke.
 2. A tool according to claim 1 wherein: a. said pin element is genErally circular in cross-sectional shape; b. said pin element first surface is defined by a flat area on said pin; and c. said pin element second surface is defined by the rounded outer surface of the pin element.
 2. a follow block mounted for longitudinal movement relative to the guide in contact with the rear fastening element in the row;
 2. linkage means including cam-cam follower means connected between the handle and the movable means; h. said movable means includes a pivotally mounted member engaging the ram means during the arming stroke and spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke; i. said linkage means includes:
 2. a plate member defining a cam surface mounted on the other end of the link member; and
 2. a second edge parallel to the first edge spaced from said axis of rotation by a distance approximately equal to said predetermined distance plus the distance which said projection protrudes from said work piece contacting surface.
 2. a manually operable lever means for rotating the pin element into said second angular position upon the completion of the arming stroke to bring the said second surface into contact with the pivotally mounted member to pivot it out of engagement with the ram means to thereby permit movement of the ram means through the driving stroke.
 2. a plate member defining a cam surface mounted on the other end of the link member; and
 2. a follow block mounted for longitudinal movement relative to the guide in contact with the rear fastening element in the row;
 2. linkage means including cam-cam follower means connected between the handle and the movable means.
 3. spring means normally urging the follow block forward along said guide to incrementally advance the row of fastening elements toward the driving station upon completion of the driving stroke; and
 3. a cam follower mounted on the handle and engaging said cam surface. j. said release means includes:
 3. spring means normally urging the follow block forward along said guide to incrementally advance the row of fastening elements toward the driving station upon completion of the arming stroke;
 3. A tool for driving a fastening element into a work piece comprising: a. a frame; b. magazine means mounted on the frame for feeding a fastening element to a driving station; c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station; d. said magazine means including:
 3. a cam follower mounted on the handle and engaging said cam surface.
 3. a rearwardly facing surface on the follow block engageable with the sloping cam surface to tilt the follow block into an inclined attitude to bring said normally disengaged stop surfaces into engagement thereby preventing forward movement of the follow block along said guide.
 3. spring means normally urging the follow block forward along said guide to incrementally advance the row of fastening elements toward the driving station upon completion of the driving stroke; and c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station. d. movable means engageable with the ram means for advancing the ram means through the arming stroke, said movable means includes:
 4. locking means for holding the follow block at the rear end of the guide for purposes of reloading the tool with a new row of fastening elements; c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station; d. movable means engageable with the ram means for advancing the ram means through the arming stroke; e. release means for effecting disengagement between the ram means and the movable means upon completion of the arming stroke; f. actuating means for moving the movable means including:
 4. In a tool for driving a fastening element into a recessed surface in the work piece, said tool including a housing and means within the housing operable upon activation to drive said fastening element from a driving station within the housing into the recessed surface, said tool being adapted to be held against the work piece during driving the improvement in combination therewith which comprises: a. a projection aligned with the driving station and protruding from the surface of tool which contacts the work piece during driving, said projection being adapted to extend into said recess in the work piece; b. an adaptor block rotatably mounted on the housing and having:
 4. locking means for holding the follow block at the rear end of the guide for purposes of reloading the tool with a new row of fastening elements, said locking means including: a. normally disengaged rearwardly and forwardly facing stop surfaces on the guide and follow block, respectively; b. a cam stop element on the guide having a sloping forwardly facing cam surface positioned in the path of rearward movement of the follow block; and c. a rearwardly facing surface on the follow block engageable with the sloping cam surface to tilt the follow block into an inclined attitude to bring said normally disengaged stop surfaces into engagement thereby preventing forward movement of the follow block along said guide. e. movable means engageable with the ram means for advancing the ram means through the arming stroke: f. release means pivotally mounted on the frame for effecting disengagement between the ram means and the movable means upon completion of the arming stroke; g. actuating means for moving the movable means including:
 5. The improvement according to claim 4 wherein: a. said adaptor block includes a recess extending through said first and second edges, said last mentioned recess being adapted to receive a portion of the housing into mating engagement therewith; b. said adaptor is spring biased into mating engagement with said housing; and c. said projection defines a tapering longitudinal rib.
 6. A tool for driving a fastening element into a work piece comprising: a. a frame; b. magazine means mounted on the frame for feeding a fastening element to a driving station, said magazine means including:
 7. A tool according to claim 6 wherein: a. said locking means includes:
 8. A tool according to claim 6, wHerein: a. each of said fastening elements is a nail; b. said guide defines an elongated channel for slidably receiving a row of said nails; and c. the follow block is slidably mounted for longitudinal movement within said channel.
 9. A tool according to claim 6 wherein the stop surfaces, the cam stop element, the rearwardly facing surface on the follow block are positioned exteriorly of said channel.
 10. A tool according to claim 7 wherein: a. said movable means includes a pivotally mounted member engaging the ram means during the arming stroke and spring means normally holding the pivotally mounted member in engagement with the ram means during the arming stroke; and b. said linkage means includes:
 11. A tool for driving a fastening element into a work piece comprising a. a frame; b. magazine means mounted on the frame for feeding a fastening element to a driving station, said magazine means including:
 12. A tool according to claim 11 wherein: a. said pin element is generally circular in cross-sectional shape; b. said first pin element surface is defined by a flat area on said pin; and c. said second pin element surface is defined by the rounded outer surface of the pin element.
 13. A tool according to claim 11 wherein: a. said retaining means includes:
 14. A tool for driving a fastening element into a work piece comprising: a. a frame; b. magazine means mounted on the frame for feeding a fastening element to a driving station; c. spring loaded ram means mounted on the frame for movement through an arming stroke against the force of the spring in a direction away from the driving station and back toward the driving station through a driving stroke under the force of the spring into driving contact with a waiting fastening element situated at the driving station; d. stop means disposed in the path of movement of the ram means for stopping movement thereof through the driving stroke at a point such that the fastening element engaging surface of the ram means extends externally of the housing; e. driving means mounted on the frame for engaging the ram means and moving the ram means through the arming stroke, said driving means disengaging the ram means at the end of the arming stroke; and f. lever means pivotally mounted on said frame, said lever means having first and second ends positioned with the first of its ends beneath the bottom of said ram means when the ram means is at the end of the driving stroke and the other end of said lever means being engageable by the driving means to pivot the lever means causing the first end to raise the ram means to a position where the ram is engageable by the driving means. 